Zanabazar junior

Lore & Background

The holotype specimen of Zanabazar junior, cataloged as IGM 100/1, was discovered in 1964 at the Bügiin Tsav locality of the Nemegt Formation in Mongolia. It was initially described by paleontologist Rinchen Barsbold in 1974 as a new species of Saurornithoides, named Saurornithoides junior. The specimen includes a nearly complete skull and braincase, part of the pelvis, some tail vertebrae, and parts of the right hindlimb. The preserved vertebrae are completely fused, indicating that this individual was an adult at the time of death.

Reader's Guide

Zanabazar junior holds significance as one of the largest and most derived troodontid dinosaurs from Asia, providing insight into the evolution of this group during the Late Cretaceous. Its reclassification from Saurornithoides to its own genus in 2009 resolved taxonomic uncertainty and highlighted the diversity of troodontids in Mongolia. The holotype's well-preserved skull and fused vertebrae offer valuable anatomical data, including evidence of adult maturity. Although initially thought to be the largest troodontid, later finds like Latenivenatrix from North America have since exceeded it in size. Zanabazar's phylogenetic position, as shown in a 2014 cladogram, places it among derived troodontids, contributing to understanding of the family's evolutionary relationships. Its naming after a prominent religious figure also reflects the cultural context of Mongolian paleontology.

Did You Know?

• Zanabazar was originally described as a new species of Saurornithoides in 1974.
• Zanabazar was one of the largest known Asian troodontids, reaching 2.3 m in length.
• The genus was named after Zanabazar, the first spiritual head of Tibetan Buddhism in Mongolia.